Sherman's decision is for practical and psychological reasons.
Psychologically speaking, there's no reason for Sherman to show his cards to the Bears so early in the week.
Practically speaking, after missing both minicamps, training camp and the first week of the season, McKenzie is behind physically and mentally. Sherman said McKenzie arrived in great shape, but being in great shape physically isn't quite the same as being in football shape. Until taking part in Wednesday's practice, McKenzie hadn't worked against NFL-caliber wide receivers and hadn't hit anybody since the January playoff loss at Philadelphia.
With the Packers operating a new defensive scheme, McKenzie has to learn in one week what his teammates have digested since the postdraft minicamp in April.
"We keep trying to push the envelope in regard to Mike's adaptability to the defense and also to the game because he hasn't been out there very much," Sherman said. "Whether he will be available on Sunday, I'm going to wait and hold on that."
With the Packers granted a two-week roster exemption, certainly there's no rush to get McKenzie into the lineup. On Monday, Green Bay beat a Carolina team that wasn't blessed with great talent at wide receiver. On Sunday, Green Bay faces a Bears team that has a weaker passing game than Carolina's. Chicago traded its star wide receiver, Marty Booker, during training camp to get standout Dolphins pass rusher Adewale Ogunleye.
With Booker gone, Chicago's top receiving threat is David Terrell. The eighth pick in the 2001 draft, the 6-foot-3 Terrell was on the threshold of being a bust entering this season. In his first three seasons, Booker averaged less than 30 catches per year. Last year in 16 games, Terrell started seven times and caught 43 passes for just 361 yards and a touchdown.
A new coaching staff and new offensive scheme seems to have given Terrell new life. In the opener against Detroit, Terrell finally flashed some of his vast potential. He caught five passes for 126 yards and ran the ball once for 20 yards.
The other starter is Bobby Wade, a fifth-round pick last season who caught a dozen passes. The 6-foot-4 Justin Gage, who had a chance to beat out Terrell this summer, is the third receiver. He caught 17 passes with a per-catch average of 19.8 yards as a rookie fifth-round pick last season. Daryl Jones, with eight catches in his first three seasons, is No. 4.
Like quarterback Rex Grossman, the potential is there for the Bears to have a good passing game, but potential is not productivity.
With all of that said, Sherman can't help but look at the schedule and see a trip to pass-happy Indianapolis coming next week. Certainly, McKenzie would be better prepared to face Peyton Manning and the Colts if he gets at least some action against the Bears.
Being a veteran and because the scheme isn't totally different than what the Packers ran last season, McKenzie isn't miles behind from a mental standpoint. Defensive backs coach Kurt Schottenheimer said McKenzie "seems to understand some of the new things" in the defense.
The Packers have said veteran Michael Hawthorne will start Sunday at McKenzie's left cornerback spot, based on a solid performance against the Panthers. If he suits up, McKenzie would work in the dime (six defensive backs) grouping.
"If you dress him, you use him," Schottenheimer said.
If McKenzie does dress, then the Packers will lose their roster exemption and will have to release a player to get to the 53-player limit.
The last Packer to arrive after a long holdout is running back Dorsey Levens. He signed just before the season opener and wound up breaking his leg in Week 2. The possibility of an injury is on Sherman's mind.
"I wouldn't put him out there if he was not in pretty good shape, which he is," Sherman said. "We've run him after practice, run him during practice. From a conditioning standpoint, I believe he's fine. Obviously, you want to avoid that injury problem but at some point you have to let him loose as well. If I didn't feel comfortable with that, I certainly wouldn't put him out there on Sunday."